2 Product overview
Festo – MPAL-VI-EN – 2017-07a – English 37
2.8 Functional description
2.8.1 Main and auxiliary power supply
The main supply of the valve terminal with operating pressure can be provided via a supply module
(è Fig. 2.5) or via a right end plate with supply ports (è Fig. 2.6).
For additional supplies, supply modules or vertical supply plates can be used.
Additional supplies may be required in the following typical cases:
– The valve terminal has several pressure zones.
– Many valves on a valve terminal are simultaneously switched to being pressurised or exhausted.
2.8.2 Exhaust air
The exhaust air ducts (3) and (5) for the working air can be exhausted in the following manner:
– Common exhausting via a supply module with a flat plate silencer or via an exhaust air plate for
ducted exhaust air
– Separate exhausting via a right end plate with supply ports
The pilot exhaust air (82/84) is exhausted via a port on the right end plate.
2.8.3 Vacuum or low-pressure operation
– Vacuum operation: vacuum (–0.9…0bar) at supply port (1)
– Low-pressure operation: low pressure (0…3bar) at supply port (1)
The following conditions must be fulfilled:
– The valve terminal is operated with an external pilot air supply.
– The valve terminal is equipped with vacuum-compatible or low-pressure-compatible valves. Valves that
are not vacuum-compatible or low-pressure-compatible are operated via separate pressure zones.
Pressure zone Valves
Pressure zone with vacuum or low pressure
supply via supply port (1)
The pressure zone is only equipped with
vacuum-compatible or low-pressure-compatible
valves è Appendix A.1.3 and Appendix B.1
Pressure zone with overpressure supply via
supply port (1) è Appendix A Fig. A.1
The pressure zone can also be fitted with the
following valves which are not vacuum- or
low-pressure-compatible:
– 2x 3/2-way valves (ID codes H, K and N)
– 2x 2/2-way valves (ID codes D and I)
Tab. 2.8 Valves compatible with vacuum or low pressure
Valves for the switching of vacuum
Install a filter in the suction line to prevent malfunctions caused by foreign matter sucked into
the line.
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